Means for automatically weighing material on conveyer-belts.



H. COMSTOUK.

MEANS FOR AUTOMATICALLY WEIGHING MATERIAL ON CONVEYER BELTS.

APPLIOATION FILED JULY 27, 1911. RENEWED MAY 31, 1913.

1,067,972. Patented Ju1y22, 1913.

'F i Z.

I llNITED STATES PATENT OFFICE.

HARRY COMSTOCK, OF MINEVILLE, NEW YORK.

MEANS FOR AUTOMATICALLY WEIG-HING MATERIAL ON CONVEYER-IBELTS.

Specification of Letters Patent.

Application filed July 27, 1911, Serial No. 640,920. Renewed May 31,1913. Serial No. 771,112.

T 0 all whom it may concern:

Be it known that I, HARRY COMSTOCK, a citizen of the United States,residing at Mineville, county of Essex, and State of New York, haveinvented certain new and useful Improvements in Means for Automaticallyl/Veighing Material on Conveyer- Belts, of which the following is aspecification.

This invention relates to means for automatically weighing material onconveyer belts.

The amount of material passing over a conveyer belt in a given length oftime is the product of the weight of the material and the speed of thebelt. The present invention is based upon this fact and it has for itsobject the provision of novel electrical means for automaticallyindicating or recording the amount of material passing over a conveyerbelt and so arranged that the instruments may be in the office at apoint distant from the conveyer belt whose contents are being measured.

In the present invention, by the use of the novel electricalinstrumentalities and circuit connections, I entirely obviate theemployment of delicate weighing devices which have to be positioned ator near the' belt itself, as has heretofore been the case, and providemeasuring apparatus which is reliable almost to perfection, practicallyimpossible to get out of order, and may be readily and inexpensivelyinstalled, as will more fully appear hereinafter.

In the accompanying drawings: Figure 1 illustrates the inventiondiagrammatically; and Fig. 2, is a detail plan showing an arrangementfor driving the conveyer belt and generator by the same power.

A represents a cross-section of a conveyer belt. 7 This maybe supportedon a platform such as used on platform scales, or, in the manner shownin the drawings, where L represents a lever fulcrumed at a point exactlyintermediate its ends at C and having one end B connected by asuspending device B to the conveyer belt so that the latter is suspendedfrom the lever L while perfectly free to run relation to the lever andsaid suspending device 13'. A spring E which is secured to any suitablepermanent member F, is connected at D to the other end of thelever L. Itwill be seen, therefore, that any change in the weight on the conveyer Awill cause a corresponding compression or deflection of the spring E.

G represents an arm which is connected to or actuated by the lever L,and carries a contact G adapted to play overthe variable resistance H.The variable resistance H and the arm G may be a rheostat of any formWhose temperature coeflicient of the resistance material will benegligible.

I designates adirect current generator whose potential is maintainedconstant. Any means for supplying a direct current with a constantpotential may be-employed in this connection. One terminal of thissource of direct current with constant potential is connected to the armG, and the other terminal is connected to the current coil of a directcurrent wattmeter K. The other terminal of the current coil of thewattmcter K is connected to the variable resistance H. The terminals ofthe potential coil of the wattmeter K are connected to the terminals ofa direct current generator J having permanent field magnets and drivenby the same source of power X that drives the conveyer belt A as, forinstance, by a belt Y running to the head or tail conveyer pulleyPatented July 22, 1913.

so that the speed of this direct current generator J varies directly inproportion to the speed of the conveyer belt A and since the poles ofthe generator J are permanent magnets, the voltage of the generator Jsupplied to the potential coil of the wattmeter K, will vary directlywith the speed of the conveyer belt. Other driving arrangcmentsmay beused for this purpose. The current through the current coil of thewattmeter K will vary directly with the amount of resistance H in thecircuit of the generator I since the potential of the generator Iremains constant.

Furthermore, the amount of resistance lIlcluded in the circuit of thegenerator I and current coil of the wattmeter K varies directly with themovement of the arm G, which, in turn, varies directly with the movementof the lever L, and consequently, with the movement of the conveyer beltA up or down according to the weight of the material which is passingthereoven, The dial of they wattmeter K is graduated to read 1n poundsor tons and the torque of themeter is the product of the potential fromgenerator J and the current from the generator I.

By the provision of electrical means re- ,lated and operating as setforth, ,there remains no necessity for providmg at the con- I veyer beltany delicate or complicated auy a conveyer belt, and,

tomatic Weighing'mechanism, and the wattmeter may be placed in theofiice or any other convenient place distant from the con- ,veyer belt.

The invention is adapted for use in any connection where it is desiredto indicate or record the amount of material passing overplicatedpartsand the utilization of electrical apparatus as aforesaid,the system will indicate or record the exact amount of material passingover the conveyer with as great accuracy as it is possible to obtain.

I'cla'nn asnew and desire to secure by Letters Patent, is

1. In an electrlcal weighing apparatus, the combination with a conveyerbelt, of an electrical generator driven at a speed varying substantiallyexactly in proportion to that of the conveyer belt and having aconstantly due to the lack of com- Any excited field, a circuit, asource of current supply at constant potential for said circuit, meansfor automatically varying the resistance of said circuit in directproportion to the rise and fall of the conveyer belt, and

an electrical indicator in the circuit aforesaid and also in circuitwith the electrical generator first-named.

2. In an electrical weighing apparatus, the combination With a conveyerbelt, of an electrical generator driven 'at a speed varyingsubstantially exactly in proportion to that of the conveyer belt andhavinga constantly excited field, a circuit, a source of current supplyat constant potential for said circuit, a

variable resistance included in said circuit,

a lever moved in one direction or the other as the conveyer belt risesor falls under its load, a spring counteracting and balancing theconveyer belt, means operated by saidlever for varying the resistanceaforesaid in direct proportion to the rise and fall of the conveyerbelt, and a Wattmeter Whose cur-- rent coil is in the circuit aforesaidand whose potential coil is in the cii'cuit'ofthe electrical generatorfirst-named.

In testimony whereof I hereunto aflix my slgnature in presence of twowitnesses.

H. OOMSTOCK. Witnesses:

JOHN L. SHEA, SAMUEL SHAPIRA.

